You’ve probably heard by now that a “drink to your health” is more than just a toast. Having a glass of alcohol with dinner may have health benefits for some people with diabetes.

Some researchers have observed that drinking a moderate amount of alcohol seems to provide benefits to people with type 2 diabetes by potentially reducing their risk of heart disease and stroke. Moderate drinking may help other people reduce the risk of developing type 2 diabetes. The data are limited for type 1 diabetes, and there is concern about hypoglycemia when drinking alcohol and using insulin.

What is a moderate amount of alcohol? It normally is considered to be one drink a day for a woman and two drinks a day for a man. (See “Moderate Drinking,” below.)

Large population studies show moderate drinkers have a “lower risk of essentially all of the diseases of aging” compared with people who either don’t drink or drink too much, says R. Curtis Ellison, MD, codirector of the Institute on Lifestyle & Health at Boston University School of Medicine, which reviews research on alcohol and health. These diseases include coronary artery disease, stroke, dementia, type 2 diabetes, and osteoporosis. Ellison says there are many good social and religious reasons that some people choose not to drink, but for people who choose to consume alcohol, the safest and healthiest way to drink is a moderate amount daily, preferably with meals.

Ellison sees mostly positive benefits of moderate drinking and says “any type of alcohol beverage will offer some protection,” whether it is wine, beer, or whiskey. No matter the type of alcohol, it is better to consume a moderate amount of alcohol daily—but don’t binge.

Ellison adds that moderate drinking may offer some protection against developing type 2 diabetes. He noticed that in long-term studies, “the ones who will develop diabetes are more likely to be nondrinkers or heavy drinkers rather than the moderate drinker.” This doesn’t prove that alcohol is the reason, but is a correlation that intrigues researchers.

A Large Study

The most recent observations of the protective benefits of moderate drinking focus on data from a large multinational diabetes study called ADVANCE. This study, with over 11,000 participants, collected medical and lifestyle histories that included questions on drinking. Among the 20 countries included in the study, use of alcohol ranged from less than 10 percent of the population in Asia to 51 percent in Eastern Europe.

One observation noted an “association between mild to moderate consumption and a lower incidence of retinopathy and nephropathy,” according to lead author Graham Hillis, MD, PhD, director of the cardiovascular division of the George Institute for Global Health in Sydney, Australia. Translation: Moderate drinkers might have fewer diabetes-related complications in their eyes and kidneys. Hillis says that other studies have paid limited attention to how drinking may affect these small blood vessel conditions.

The ADVANCE data also indicated but did not prove that moderate drinking lowers the risk of heart attack, stroke, and early death. The data suggest that drinking more than moderate amounts increases those risks.

About Blood Glucose

Washington State University’s Joshua Neumiller, PharmD, the lead reviewer of literature about diabetes and alcohol for the American Diabetes Association nutrition recommendations committee says that moderate alcohol consumption “can have some modest improvements in glycemic control.”

Neumiller cites a Kaiser Permanente study in which a review of health records found that moderate drinkers in the system’s registry of both type 1 and type 2 diabetes had lower A1Cs (a measure of average blood glucose control) than nondrinkers and people who consumed large amounts of alcohol.

But Neumiller also warns about the hazard of delayed low blood glucose levels after drinking alcohol for people using insulin or medications that stimulate the body to produce more of its own insulin (sulfonylureas and glinides).Because of this risk, he offers two tips:

Drink alcohol with a meal to have some carbohydrate in your system.

Check your blood glucose levels during and after drinking alcohol to avoid hypoglycemia.

Moderation is the key, he says. People should avoid large quantities of alcohol because managing blood glucose and carb counting while consuming beverages that contain alcohol becomes very complicated, especially with mixed drinks or beers containing a lot of carbs. Neumiller gives the example of somebody drinking a rum and Coke, where the high sugar content of the soda can cause a spike in blood glucose, but the longer-lasting blood glucose effects of the alcohol can create a hypoglycemic event. The danger of lows can last as long as 24 hours after drinking the alcohol. And everybody responds differently to alcohol, so the effects aren’t predictable.

The effect of alcohol on blood glucose levels is complicated, Neumiller says. “You don’t have the normal counter-regulatory hormone [defense against hypoglycemia] response, because the liver is busy metabolizing the alcohol and isn’t able to correct for hypoglycemia as it normally would.” It is always wise to discuss drinking, your medications, and your health status with a health care professional—before you take that first sip.

What about harmful effects? Any health benefits of alcohol are lost if you drink too much. Excessive drinking and binge drinking is bad for your health and a leading cause of preventable death. There are also groups of people who should not drink. (“Do Not Drink,” below.)

To Drink or Not to Drink?

Although Ellison, Hillis, and Neumiller describe the potential benefits of drinking alcohol in moderation, none of their observations come from the gold standard of clinical research known as a randomized controlled trial. Finding the true risk or benefit of moderate alcohol use would involve recruiting thousands of people with diabetes, giving one set one to two drinks a day, and providing a second set with fake alcohol—plus following them for years. Of course, this type of study will not likely be done. So based on existing research, the three professionals sum up their takeaway messages about drinking alcohol:

Ellison: Drinking is an individual choice, and “if you do drink alcohol, we know that the safest and the healthiest approach is to have small amounts. Don’t binge and obviously don’t go driving after you’ve had your drinks; drink a small amount on a regular basis.”

Hillis: If someone “drinks excessively, I advise them strongly to reduce their consumption and [I] point out the adverse health consequences if they don’t. If people enjoy alcohol socially and in moderation, then the good news is that they may possibly derive some health benefits from it—but the evidence is not absolutely clear, and the benefits are likely modest. If they don’t drink alcohol, I tell them not to worry about it—the only good reason to drink alcohol is to enjoy it.”

Neumiller: “I tell my patients there is some evidence that drinking one to two drinks a day may have some benefits in people with type 2 diabetes, but if you do drink, make sure you are eating and not going too long between meals. I also stress that when people do get a little bit intoxicated they are less likely to recognize signs of hypoglycemia.”

Editors’ Note: If you currently drink no alcohol, don’t start simply for the possible health benefit. The evidence of benefit is based on observation, not proof, and the possible reduction of heart attack and stroke risk may not make a big difference in your health. In addition, individuals prone to alcoholism may succumb to this terrible affliction if they make a change from being a teetotaler to drinking, even in small amounts. A family history of alcohol or substance abuse could be a clue that you may be at risk for alcoholism. Talk to your health care team to determine whether drinking alcohol is safe for you.

Moderate Drinking

Moderate drinking is generally defined as one drink per day or less for adult women and two drinks per day or less for adult men. The American Diabetes Association defines one alcohol-containing drink as 12 ounces of beer, 5 ounces of wine, or 1.5 ounces of distilled spirits. Each of these contains about 15 grams of alcohol.

Do Not Drink

People who should not drink alcohol are those with a history of alcohol abuse or dependence, women during pregnancy, and people with medical conditions such as liver disease, pancreatitis, advanced neuropathy (nerve damage), or high levels of triglycerides in their blood.

Excessive Drinking

Excessive drinking accounts for 1 in 10 deaths among working-age adults in the United States, according to the Centers for Disease Control and Prevention. Excessive alcohol use, including underage drinking and binge drinking (drinking on one occasion five or more drinks for men and four or more drinks for women), can lead to an increased risk of health problems such as injuries, violence, liver diseases, and cancer.